Noxious Weeds

Pawnee County Noxious Weed Control Authority

The Director of the Nebraska Department of Agriculture
establishes which plants are noxious and the control measures to be
used in preventing their spread. The following non-native weeds have
been officially designated as noxious in Nebraska:

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Saltcedar(Tamarix
ramosissima)

Lifespan: Perennial Shrub or small tree

Origin: Eurasia

Stem: 3 - 20 feet tall

Flowering Dates: April - September

Reproduction: Seeds, root sprouts, buried stems

Saltcedar grows in salt marshes, flood plains, lakeshores and
along rivers and streams. A mature saltcedar plant can absorb 200
gallons of water and dense stands may cause springs and small streams
to dry up. Saltcedar seed resembles the size and color of pepper
and spreads by wind and water. A mature plant can produce as many
as 500,000 seeds per year. Branches that are cut and left in a warm
moist area will regrow.

Roots: Deep, spreading, brown with numerous pink buds
which may produce new shoots or roots.

Musk Thistle (Carduus
nutans L.)

Life Span: Biennial or occasionally an annual. Rosette
formed first year.

Stems: Up to 6 feet tall; main stem and major branches
are hairless. The stem bearing flower head is covered with fine
gray hair with the first few inches below the flower head having
no leaves attached.

Leaves: Dark green, prominent light green midrib, usually
smooth or hairless on both sides. Deeply lobed with spiny margins
up to 20 inches in length.

Inflorescence: Large, solitary 1 to 2-1/2 inches in diameter,
usually noding slightly. Deep rose or purple color. Average plant
produces 5,000 to 10,000 seeds; some up to 20,000 seeds.

Plumeless Thistle (Carduus
acanthoides L.)

Life Span: Biennial or occasionally an annual. Rosette
formed in first year.

Leaves: Alternate, deeply divided into narrow segments
and covered with short hairs. Leaves much smaller at top of plant
and becoming more linear. Seedling leaves form a rosette.

Inflorescence: Numerous terminal and axillary blossoms
3/4 inch in diameter, composed of pink to purple disk flowers. Each
head surrounded by leaf-like bract with dark tips and a fringe of
bristly hairs. Flowers June through October.

Roots: Stout, elongated taproot.

Purple Loosestrife
(Lythrum salicaria L.)

Life Span: Perennial

Stems: Erect, 4-angled, hairless to pubescent, not highly
branched, usually from a woody base.